The present invention relates to absorbent materials and, more particularly, the present invention relates to sorbent materials and wipes for industrial applications.
Generally, industrial sorbent materials have been used heretofore to absorb or xe2x80x9cpick-upxe2x80x9d unwanted liquids that result from spills, leaks or other means. As an example, sorbent materials have been used as a means of collecting or absorbing oil and oil based liquids. Additionally, sorbent materials have likewise been used to collect or absorb aqueous liquids. As a specific example, sorbent materials have been used as floor mats in shops or mills to ensure that a working area does not become slippery or otherwise unsafe because of liquids spilled upon the floor. Sorbent wipes have also been used to remove undesirable liquids from workbenches and other surfaces. Further, sorbent materials have also been utilized as a means for retaining hazardous or environmentally unfriendly liquids, such as within an oil boom.
Sorbent materials desirably have a high absorption capacity since this allows for more efficient use of the sorbent material both in terms of the ability to use less material to absorb more liquids and in reducing the amount of saturated material for disposal. Disposal of wet sorbent material can be quite expensive where hazardous or environmentally unfriendly materials are absorbed since the disposal of sorbent material may require compliance with special and perhaps costly disposal protocols. In addition, the sorbent materials desirably exhibit the ability to quickly absorb or wick liquid into the article. Sorbent materials, particularly wipes, which do not quickly absorb liquids are not convenient to use when trying to clean up or remove liquids from a hard surface. Further, the sorbent material also desirably exhibits the ability to retain such liquids once wicked into the fabric. When sorbent materials cannot retain absorbed liquid they tend to leak or drip fluid once removed from the supporting medium. This can be disadvantageous in making clean up more difficult and/or by further spreading the undesirable liquids. Thus, sorbent materials that can quickly absorb significant quantities of liquids and which also have the ability to retain the same are highly desirable.
However, many sorbent materials inherently exhibit good absorption and retention characteristics for only certain types of liquids. For example, polyolefin nonwoven webs have heretofore been used to absorb oil or oil based liquids since polyolefin nonwoven wipes are inherently oleophillic and hydrophobic. Polyolefin nonwoven wipes need to be treated in some manner in order to impart good wetting characteristics or absorbency for water and other aqueous liquids. Thus, in order to improve the absorbency characteristics of sorbent articles, various wetting chemistries have been applied thereto. As an example, U.S. Pat. No. 4,328,279 to Meitner et al. discloses use of a low linting nonwoven web for use as a wipe in clean room applications. Polyolefin nonwoven wipes are inherently hydrophobic but by addition of a wetting chemistry, comprising an alkyl phenoxy ethanol and dioctyl sulfosuccinate, Meitner achieves a low linting sorbent material that exhibits good absorbent characteristics for both water and oil. Various other wetting chemistries have also been used in connection with sorbent materials to improve their absorbency characteristics. Therefore, when the composition of the liquid to be absorbed is known ahead of time, a suitable sorbent material can be selected for this specific purpose.
Research facilities, manufacturing facilities, repair shops, medical institutions and other entities often utilize or come in contact with a wide variety of chemicals or other compounds in their daily operations. Thus, the particular class or composition of the liquid sought to be absorbed can vary from day-to-day and even application-to-application. Moreover, the particular composition of liquids spilled or errantly released may be unknown to those with the responsibility to clean up or contain the same. However, as indicated above, many sorbent materials have good wicking and absorption characteristics only for certain specific liquids and do not exhibit adequate absorbency for other types of liquids. For example, a sorbent wipe may exhibit good affinity for oil based suspensions or emulsions and not for water. Further, with regard to aqueous liquids, the wipe may exhibit good absorbency characteristics for acidic aqueous liquids but not basic aqueous liquids and vice-versa. Thus, the problem often arises that for any given spill the sorbent material may be inefficient or entirely ineffective in absorbing and/or retaining that particular liquid.
In addition to absorbency, sorbent materials desirably have the ability to quickly dissipate charges since they are then less likely to develop or release a static charge. In this regard, sorbent materials used in proximity to electrically sensitive devices, such as integrated circuits and/or micro-electronic devices, desirably have good anti-static properties. Although the current generated from static electricity is small by many standards, it is relatively large with respect to the electrical load intended to be carried by interconnection patterns within integrated circuits and other micro-electronic devices. Thus, static electricity can be fatally destructive to such devices. In addition, when collecting or containing flammable liquids it is likewise highly desirable that the web have excellent anti-static properties in order to avoid igniting the same. However, although anti-static properties are often desirable, use of conventional ionic compounds that impart anti-static properties can negatively impact emulsion stability, processability and absorbency characteristics of the sorbent material.
Therefore, there exists a need for a versatile sorbent material that has excellent absorbency characteristics, both in terms of rate and quantity, for a broad range of liquids having varied physical and chemical composition. Additionally, there exits a need for sorbent materials capable of absorbing both polar and non-polar liquids such as for example, both aqueous and hydrocarbon (i.e. oil) based solutions, emulsions and/or suspensions. Further, there exists a need for such a wiper capable of efficiently and effectively absorbing both highly acidic and basic liquids. Further, there exists a need for such a sorbent material having good anti-static properties. Still further, there exists a need for such sorbent materials that are stable (e.g. chemically and thermally) and that are capable of high-speed production.
The aforesaid needs are fulfilled and the problems experienced by those skilled in the art overcome by the sorbent materials of the present invention comprising a porous substrate having, upon its surface, a wetting chemistry comprising: a glycoside and/or a glycoside derivative; a fatty acid ester ethoxylate; and one or more surfactants selected from the group consisting of alkyl alcohol ethoxylates and halogenated analogs thereof, aryl alcohol ethoxylates and halogenated analogs thereof, alkyl sulfonates, alkyl sulfates, alcohol ether sulfates, alkyl phosphates and aryl analogs thereof, alkyl phosphonates and aryl analogs thereof, alkyl sulfosuccinates and/or sulfated fatty acid esters. The wetting chemistry is desirably located substantially throughout the porous substrate such as, for example, upon fiber surfaces throughout a nonwoven web. In a further aspect, the wetting chemistry desirably comprises about 0.1% to about 20% by weight of the sorbent material.